xref: /freebsd/sys/contrib/openzfs/lib/libspl/include/sys/random.h (revision 8ccc0d235c226d84112561d453c49904398d085c)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
26  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
27  */
28 
29 #ifndef _SYS_RANDOM_H
30 #define	_SYS_RANDOM_H
31 
32 extern int random_get_bytes(uint8_t *ptr, size_t len);
33 extern int random_get_pseudo_bytes(uint8_t *ptr, size_t len);
34 
35 extern void random_force_pseudo(boolean_t onoff);
36 
37 static __inline__ uint32_t
38 random_in_range(uint32_t range)
39 {
40 	uint32_t r;
41 
42 #if !defined(__APPLE__) || !defined(IN_BASE)
43 	ASSERT(range != 0);
44 #endif
45 
46 	if (range == 1)
47 		return (0);
48 
49 	(void) random_get_pseudo_bytes((uint8_t *)&r, sizeof (r));
50 
51 	return (r % range);
52 }
53 
54 #endif	/* _SYS_RANDOM_H */
55